Subject: [PATCH v3 07/13] arm64, execmem: extend execmem_params for generated code allocations

From: Mike Rapoport <[email-masked]>
Date: Mon, 18 Sep 2023 10:29:49 +0300

From: "Mike Rapoport (IBM)" <[email-masked]>

The memory allocations for kprobes and BPF on arm64 can be placed
anywhere in vmalloc address space and currently this is implemented with
overrides of alloc_insn_page() and bpf_jit_alloc_exec() in arm64.

Define EXECMEM_KPROBES and EXECMEM_BPF ranges in arm64::execmem_params and
drop overrides of alloc_insn_page() and bpf_jit_alloc_exec().

Signed-off-by: Mike Rapoport (IBM) <[email-masked]>
---
 arch/arm64/kernel/module.c         | 13 +++++++++++++
 arch/arm64/kernel/probes/kprobes.c |  7 -------
 arch/arm64/net/bpf_jit_comp.c      | 11 -----------
 3 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index cd6320de1c54..d27db168d2a2 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -116,6 +116,16 @@ static struct execmem_params execmem_params __ro_after_init = {
 			.flags = EXECMEM_KASAN_SHADOW,
 			.alignment = MODULE_ALIGN,
 		},
+		[EXECMEM_KPROBES] = {
+			.start = VMALLOC_START,
+			.end = VMALLOC_END,
+			.alignment = 1,
+		},
+		[EXECMEM_BPF] = {
+			.start = VMALLOC_START,
+			.end = VMALLOC_END,
+			.alignment = 1,
+		},
 	},
 };
 
@@ -140,6 +150,9 @@ struct execmem_params __init *execmem_arch_params(void)
 		r->end = module_plt_base + SZ_2G;
 	}
 
+	execmem_params.ranges[EXECMEM_KPROBES].pgprot = PAGE_KERNEL_ROX;
+	execmem_params.ranges[EXECMEM_BPF].pgprot = PAGE_KERNEL;
+
 	return &execmem_params;
 }
 
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index 70b91a8c6bb3..6fccedd02b2a 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -129,13 +129,6 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
 	return 0;
 }
 
-void *alloc_insn_page(void)
-{
-	return __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, VMALLOC_END,
-			GFP_KERNEL, PAGE_KERNEL_ROX, VM_FLUSH_RESET_PERMS,
-			NUMA_NO_NODE, __builtin_return_address(0));
-}
-
 /* arm kprobe: install breakpoint in text */
 void __kprobes arch_arm_kprobe(struct kprobe *p)
 {
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 150d1c6543f7..3a7590f828d1 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -1687,17 +1687,6 @@ u64 bpf_jit_alloc_exec_limit(void)
 	return VMALLOC_END - VMALLOC_START;
 }
 
-void *bpf_jit_alloc_exec(unsigned long size)
-{
-	/* Memory is intended to be executable, reset the pointer tag. */
-	return kasan_reset_tag(vmalloc(size));
-}
-
-void bpf_jit_free_exec(void *addr)
-{
-	return vfree(addr);
-}
-
 /* Indicate the JIT backend supports mixing bpf2bpf and tailcalls. */
 bool bpf_jit_supports_subprog_tailcalls(void)
 {
-- 
2.39.2